Trajectory and aiming guide for use with fluoroscopy

ABSTRACT

A system for a trajectory and aiming guide for use with fluoroscopy is comprised of a ring holder is with a plurality of connecting arms, a radiolucent ring disk with an outer perimeter wall and a central axle on the bottom surface of the ring disk; a first rotatable disk located below the ring holder and comprised of a handle, a radiolucent disk ring with a central cutout to receive the central axle, the material of the disk comprising an embedded array of a plurality of radiopaque wires and an outer perimeter wall; a second rotatable disk located below the first rotatable disk and comprised of a handle, a radiolucent disk ring with a central cutout to receive the central axle, the material of the disk comprising an embedded array of a plurality of radiopaque wires and an outer perimeter wall; and a locking cap for the axle.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 62/111,636, filed Feb. 3, 2015, entitled TRAJECTORY AND AIMING GUIDEFOR USE WITH FLUOROSCOPY, the entire disclosure of which is hereinincorporated by reference.

FIELD OF THE INVENTION

This invention is in the field of medical devices, and more particularlydevices for aiming objects inserted into the body using x-rays.

BACKGROUND OF THE INVENTION

Fluoroscopy is used for determining the alignment and placement ofinvasive medical implants (for example, surgical screws) that areinserted into a body. Fluoroscopes using x-ray emissions are asignificant tool in orthopaedic procedures. Proper alignment andplacement of implants reduces adverse outcomes and complications for thepatient. The ultimate goal of the surgeon is to repair or replace anon-functional joint with a joint that functions as naturally aspossible. Poor placement can result in harm to adjacent organs ortissues (for example, nerves and blood vessels), discomfort, gaitproblems, degradation of the prostheses and possible revision surgery.

Fluoroscopic checks during surgery give the surgeon an opportunity toproperly align and place the implants. This is of particular importancefor the proper trajectory of screws. A surgeon who is able to quicklymake a correct determination of alignment and seating of the implantsleads to a shorter surgical time, which can result in a reducedtourniquet time, reduced anesthesia time, lower blood loss, and improvedrecovery by the patient. Implant penetration depth can be ascertained.Furthermore, frequent fluoroscopic checks increases the amount ofambient ionized radiation in the operating room, which can pose along-term health risk for the patient and surgical team. Improvements invision technology and shielded garments can reduce the amount ofradiation, but not all of the risks of exposure.

It would be desirable to have an alignment system for properly aligningthe surgical implants as quickly as possible, resulting in a betteroutcome for the patient and less exposure to radiation for the surgicalteam.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages of the prior art byproviding a system and method for a trajectory and aiming guide for usewith fluoroscopy. The trajectory and aiming guide is comprised of a ringholder with a plurality of connecting arms, a radiolucent ring disk withan outer perimeter wall and a central axle on the bottom surface of thering disk; a first rotatable disk located below the ring holder andcomprised of a handle, a radiolucent disk ring with a central cutout toreceive the central axle, the material of the disk comprising anembedded array of a plurality of radiopaque wires and an outer perimeterwall; a second rotatable disk located below the first rotatable disk andcomprised of a handle, a radiolucent disk ring with a central cutout toreceive the central axle, the material of the disk comprising anembedded array of a plurality of radiopaque wires and an outer perimeterwall; and a locking cap for the axle. The trajectory and aiming guide isremovably attachable to an x-ray receiver of a fluoroscope. The embeddedarray of a plurality of wires in a rotatable disk can be arranged in aparallel orientation. The embedded array of a plurality of wires in arotatable disk can be arranged equidistant from one another. Theembedded array of a plurality of wires in a rotatable disk can bearranged in a converging orientation. The ring holder can define fourconnecting arms. The outer perimeter walls of at least one rotatabledisk define indicia markings. The first rotatable disk and the secondrotatable disk can be interchangeable with each other. The rotatabledisk having embedded wires in a parallel array can be interchanged witha rotatable disk having embedded wires in a converging array. A methodfor determining the angular trajectory and alignment of objects insertedusing x-rays using a trajectory and aiming guide is comprised of thesteps of attaching the trajectory and aiming guide to a x-ray receiverof a fluoroscope; rotating a first rotatable disk to align embedded wirelines with a first reference axis; rotating a second rotatable disk toalign embedded wire lines with a second reference axis; determining theangular difference between the alignment of the first rotatable disk andthe alignment of the second rotatable disk.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention description below refers to the accompanying drawings, ofwhich:

FIG. 1 is a bottom view of a ring holder for a trajectory and aimingguide according to an illustrative embodiment;

FIG. 2 is a side view of a ring holder for a trajectory and aiming guideaccording to the illustrative embodiment;

FIG. 3 is a bottom view of an upper ring for a trajectory and aimingguide according to the illustrative embodiment;

FIG. 4 is a side view of the upper ring for a trajectory and aimingguide according to the illustrative embodiment;

FIG. 5 is a bottom view of a lower ring for a trajectory and aimingguide according to the illustrative embodiment;

FIG. 6 is a side view of a lower ring for a trajectory and aiming guideaccording to the illustrative embodiment;

FIG. 7 is a bottom view of the combined elements of a trajectory andaiming guide according to the illustrative embodiment;

FIG. 8 is a side view of the trajectory and aiming guide according tothe illustrative embodiment; and

FIG. 9 is a schematic view of a hip screw center-center aiming guideaccording to an alternate embodiment.

DETAILED DESCRIPTION

In an embodiment, a trajectory and aiming guide includes three parallelround disks, two of which are mounted and rotate around a centralvertical axle. The disk diameters are dimensioned so as to approximatethe diameter of the x-ray receiver of the fluoroscopy machine. FIG. 1depicts an exemplary ring holder 100. A central axle 102 is mounted andaligned on the center 104 of bottom surface 105 of the ring 100. Thecentral axle 102 is aligned with the stream of x-rays, in an up and downorientation with regards to the x-ray receiver. The ring disk 106describes a solid x-ray translucent (“radiolucent”) disk that mountsover the x-ray receiver of the fluoroscopy machine using four mountingclips 108 disposed around the outer perimeter 110 of the ring disk 106.The ring disk 106 is therefore a mounting element that fixes the deviceto a fluoroscope with a stable connection. The mounting clips 108describe connecting arms for that stable connection. In alternateembodiments, the mounting clips 108 can be constructed as mountingclamps with spring-loaded tension mechanisms, snaps, or another clampinglock. In other embodiments, it is contemplated that there can be more orfewer mounting clips. The ring holder 100 receives and retains the tworotatable rings 300, 500. The material of the ring is a rigid x-raytranslucent material, for example, high-density polyethylene (HDPE) orany radiolucent material with adequate rigidity to support theradiopaque wires. The outer diameter DR of the ring holder isapproximately 16 inches (406 mm). As noted, the outer diameter DR canvary greater or lesser depending on the diameter of the x-ray receiverof the fluoroscopy machine. In an embodiment, a flouroscopy receiver isprovided with a diameter of 15.25 inches (387 mm).

FIG. 2 is a side view of the ring holder 100 of FIG. 1. The thickness TRof the ring 106 is approximately one-quarter inch (6 mm). In otherembodiments, this thickness can vary greater or lesser. The clips 108are “U-shaped” and have a base 202, vertical portion 204 and overhang206 and are constructed to removably attach to the fluoroscope x-rayreceiver (not shown).

Rotatable rings 300 and 500 have a diameter that is the same or lessthan the ring holder 100. In one example, the first ring disk has adiameter of sixteen inches while the rotatable discs are each 15.25inches in diameter. An exemplary first ring disk 300 is shown in FIG. 3.This is an upper ring 300 and includes a handle 302 and a ring disk 304.The ring disk 304 is constructed of a rigid x-ray translucent material,for example, high-density polyethylene (HDPE). An array of a pluralityof metal wires 306 are imbedded within the material of the ring disk 304that are visible when seen on an x-ray machine (radiopaque). In anembodiment, ten wires are depicted as embedded within the material ofthe ring disk 304. In other embodiments, the number of wires can begreater or lesser, and have a regular or irregular spacing. The metalwires 306 are arranged so as to be equidistant from each other andparallel to each other. Under fluoroscopy, the disk will appear to betranslucent while the wires will be visible as an array of parallellines. The rotatable upper ring 300 rotates around axle 102 independentof the ring holder 100 and the lower ring 500 and is manipulated by thehandle 302. Center cutout 310 receives the axle 102.

FIG. 4 is a side view of the upper ring 300 and central axle 102. Theouter perimeter wall 308 can be provided with indicia lines andreference numbers in another embodiment.

An exemplary second disk ring 500 is shown in FIG. 5. This ring is thelower ring 500 and includes a handle 502 and a ring disk 504. The ringdisk 504 is constructed of the same radiolucent material as the upperdisk 300. An array of a plurality of radiopaque metal wires 506 areimbedded within the material of the ring disk 504. In an embodiment, tenwires are depicted as embedded within the material of the ring disk 504.In other embodiments, the number of wires can be greater or lesser, andhave a regular or irregular spacing. In an embodiment, the metal wires506 are arranged so as to be equidistant from each other and parallel toeach other. The rotatable lower ring 500 rotates around axle 102independent of the ring holder 100 and the upper ring 300 and ismanipulated by the handle 502. Center cutout 510 receives the axle 102.

FIG. 6 is a side view of the lower ring 500 and central axle 102. Theouter perimeter wall 508 can be provided with indicia lines andreference numbers in another embodiment.

FIG. 7 is a combined view 700 of ring holder 100, upper ring disk 300and lower ring disk 500. The imbedded wires 306, 506 are depictedrelative to each other. As noted above, upper ring 300 is rotatable in acircular movement 702 around the axle 102 by manipulation of handle 302.Lower ring 500 is rotatable in a circular movement 704 around the axle102 by manipulation of handle 502. Rotation of each ring will change theorientation of the embedded arrays of wires 306, 506. The wires 306, 506can be oriented in parallel or converging patterns. As depicted in FIGS.3, 5 and 7, the two rotatable disks define parallel line arrays. It isexpressly contemplated that a plurality of disc configurations may beconsidered It is further contemplated that digitally superimposedtrajectory guides can be projected in the software of the fluoroscopesuch that the operator can select the guide to be superimposed andchange it during the operation as needed.

In use, the trajectory and aiming guide is attached to the x-rayreceiver of the fluoroscope. Under the fluoroscope, the lines formed bythe wires are visible, as well as the underlying bones and any implantedmaterials (e.g., surgical screws, plates). The angular orientations aredetermined by rotating the first (upper) ring to align with a firstreference axis (for example, the axis of the shaft of a femur). Thesurgeon then rotates the second (lower) ring to align with a secondreference axis (for example, the trajectory of a surgical screw). Theangular difference between these two reference axes can be determined byfirst measuring the angles of each and subtracting the lesser angle fromthe higher. Indicia on the outer perimeter walls 308, 508 can beprovided for reference measurement of the relative angles and to assistthe calculation of the angular differences. For example, when theembedded wires 308 of the upper disk 300 are perpendicular to the wires508 or the lower disk 500, the angular orientation is ninety (90)degrees.

For many orthopaedic applications (e.g., the implantation ofpercutaneous screws for a hip fracture), one of the rotatable disks canbe oriented so that the embedded wires are parallel to a first referenceaxis, in an embodiment, the axis of the bone (e.g., the femoral shaft),and the second disk can be rotated to an orientation with a secondreference axis, for example, the optimal trajectory for screw placement.The optimal trajectory can then be used for implanting the screw. Giventhat the angular orientation of joints and bones can vary from patientto patient, the precise measurement and calculation of these angularorientations can result in a more efficacious outcome and recovery forthe patient.

Once the surgeon has rotated the disks to establish the optimal angularorientation, the disks can be left in position and the lines of thewires used to chart the optimal entry position for the first andsubsequent screws. This avoids the surgeon having to make additionalholes and the resultant weakening of the bone that result from multipleholes. Furthermore, the surgeon can record the alignments and settingfor future reference, both for medical records and for possible futuresurgeries.

FIG. 8 is a side view of the elements of FIG. 7. The rotatable disks300, 500 can be secured to the axle 102 by an axle locking mechanism, inthis embodiment, an exemplary locking end cap 800. In other embodiments,the axle locking mechanism 800 can be a threaded ring, threaded cap,spring-loaded lock or another such mechanism.

FIG. 9 is an alternate embodiment showing a different alignment scheme900 for the imbedded wires 306, 506, to create a converging pattern ofimplanted devices. This alignment guide can be used in the event adynamic hip screw implant was combined with an anti-rotation screw.Given that the axle locking mechanism 800 can be removed, it isexpressly contemplated that one of or both of the rotatable rings 300,500 can be substituted with a disk provided with the different alignmentscheme 900. As used herein the directional terms, such as, but notlimited to, “up” and “down”, “upward” and “downward”, “rear”, “rearward”and “forward”, “top” and “bottom”, “inside” and “outer”, “front” and“back”, “inner” and “outer”, “interior” and “exterior”, “downward” and“upward”, “horizontal” and “vertical” should be taken as relativeconventions only, rather than absolute indications of orientation ordirection with respect to a direction of the force of gravity.

It should be clear from the foregoing that the above-described deviceprovides for an accurate and readily used system for the determinationof angular orientations of bones and implantable devices by fluoroscopy.Such determinations are useful to a broad range of surgical procedures,from repairs to replacements. This can improve hip and shoulderreplacements, spinal surgeries and a wide range of other procedures.

The foregoing has been a detailed description of illustrativeembodiments of the invention. Various modifications and additions can bemade without departing from the spirit and scope of this invention.Features of each of the various embodiments described above may becombined with features of other described embodiments as appropriate inorder to provide a multiplicity of feature combinations in associatednew embodiments. Furthermore, while the foregoing describes a number ofseparate embodiments of the apparatus and method of the presentinvention, what has been described herein is merely illustrative of theapplication of the principles of the present invention. For example, alocking mechanism can be provided that locks each disk when the properorientation for that disk is established. The outer perimeter wall canbe provided with a sensor that determines the angular orientation withregard to a reference point for that disk for display on the fluoroscopeor a secondary display. As noted, the disks can be provided withembedded wire arrays that are in parallel or converging orientations.There can be more or fewer embedded wires. The disks can beinterchangeable. In other embodiments, the disks can be provided with asmall servo motor and a power source and rotated by a remote control.Accordingly, this description is meant to be taken only by way ofexample, and not to otherwise limit the scope of this invention.

What is claimed is:
 1. A system for a trajectory and aiming guide foruse with fluoroscopy comprising: a ring holder comprising: a pluralityof connecting arms; a radiolucent base; and a central axle extendingfrom the radiolucent base; a first rotatable disk rotatable relative tothe ring holder, the first rotatable disk comprising: a firstradiolucent disk ring with a central cutout, wherein the central axleextends through the central cutout, the first radiolucent disk ringcomprising an embedded array of a plurality of radiopaque wires; and asecond rotatable disk comprising: a second radiolucent disk ring with acentral cutout, wherein the central axle extends through the centralcutout, the second radiolucent disk ring comprising an embedded array ofa plurality of radiopaque wires.
 2. The system of claim 1, wherein thetrajectory and aiming guide is removably attachable to an x-ray receiverof a fluoroscope by the plurality of connecting arms.
 3. The system ofclaim 1, wherein the plurality of radiopaque wires in at least one ofthe rotatable disks are arranged in a parallel orientation.
 4. Thesystem of claim 3, wherein the plurality of radiopaque wires in at leastone of the rotatable disks are arranged equidistant from one another. 5.The system of claim 1, wherein the plurality of radiopaque wires in atleast one of the rotatable disks are arranged in a convergingorientation.
 6. The system of claim 1, wherein the plurality ofconnecting arms comprises at least three connecting arms.
 7. The systemof claim 1, wherein an outer perimeter wall of at least one of therotatable disks defines indicia markings.
 8. The system of claim 1,wherein the first rotatable disk and the second rotatable disk areinterchangeable with each other.
 9. The system of claim 8, wherein arotatable disk having embedded wires in a parallel array can beinterchanged with a rotatable disk having embedded wires in a convergingarray.
 10. A system for a trajectory and aiming guide for use withfluoroscopy comprising: a trajectory guide holder comprising: aplurality of connecting arms; a radiolucent base; and a firstradiolucent trajectory guide rotatably attached to the trajectory guideholder wherein the first radiolucent trajectory guide rotates relativeto the trajectory guide holder, the first radiolucent trajectory guidecomprising an embedded array of a first plurality of radiopaque wires;and a second radiolucent trajectory guide rotatably attached to thetrajectory guide holder, the second radiolucent trajectory guidecomprising an embedded array of a second plurality of radiopaque wires.11. The system of claim 10, wherein the trajectory and aiming guide isremovably attachable to an x-ray receiver of a fluoroscope by theplurality of connecting arms.
 12. The system of claim 10, wherein thetrajectory guide holder further comprises a central axle extending fromthe radiolucent base, and wherein the first radiolucent trajectory guidedefines a first central cutout, the central axle extending through thefirst central cutout, and wherein the second radiolucent trajectoryguide defines a second central cutout, the central axle extendingthrough the second central cutout.
 13. The system of claim 10, whereinthe embedded array of the first plurality of radiopaque wires arearranged in a parallel orientation.
 14. The system of claim 13, whereinthe embedded array of the second plurality of radiopaque wires arearranged in a parallel orientation.
 15. The system of claim 10, whereinthe embedded array of the first plurality of radiopaque wires arearranged in a converging orientation.
 16. The system of claim 10,wherein the plurality of connecting arms comprises at least threeconnecting arms.
 17. The system of claim 10, wherein an outer perimeterof at least one of the radiolucent trajectory guides defines indiciamarkings.
 18. The system of claim 10, wherein the first radiolucenttrajectory guide and the second radiolucent trajectory guide areinterchangeable with each other.
 19. The system of claim 18, wherein aradiolucent trajectory guide having embedded wires in a parallel arraycan be interchanged with a radiolucent trajectory guide having embeddedwires in a converging array.
 20. A system for a trajectory and aimingguide for use with fluoroscopy comprising: a ring holder comprising: aplurality of connecting arms; a radiolucent base; and a central axleextending from the radiolucent base; a first rotatable disk comprising:a first radiolucent disk ring with a central cutout, wherein the centralaxle extends through the central cutout, the first radiolucent disk ringcomprising an embedded array of a plurality of radiopaque wires; and asecond rotatable disk comprising: a second radiolucent disk ring with acentral cutout, wherein the central axle extends through the centralcutout, the second radiolucent disk ring comprising an embedded array ofa plurality of radiopaque wires; wherein the trajectory and aiming guideis removably attachable to an x-ray receiver of a fluoroscope by theplurality of connecting arms.